The present invention relates to a method and apparatus for covertly viewing a target using transmission of infrared radiation through an atmosphere having given atmospheric conditions.
Military and police operations at night have been a subject of great importance for many years. Many operations are covert in nature, therefore, high-intensity artificial illumination is unacceptable because it is detectable at great distances.
In the last decade a number of night imaging devices have been developed to aid soldiers and policemen in their operations. For example, filtered or shielded light sources have been used to provide illumination at night. However, these methods are unsuccessful when used to illuminate large areas because their low levels of intensity do not provide enough light to illuminate large areas.
Further, devices such as "low-light-level-goggles" and telescopes that use light-intensifiers have been developed. However, these devices are dependent upon the availability of natural light. Thus, their efficiency and usefulness degrades to an unusable level on moonless nights.